provide for the assumption by a Successor Company of the obligations of the PredecessorCompany under the Indenture or to add a Guarantor under the Indenture;     WHEREAS, each Guarantor desires to enter into such First Supplemental Indenture for good andvaluable consideration, including substantial economic benefit in that the financial performanceand condition of such Guarantor is dependent on the financial performance and condition of theSuccessor Company, the obligations hereunder of which such Guarantor has guaranteed, and on suchGuarantor’s access to working capital through the Successor Company’s access to borrowings underthe Senior Credit Facilities; and     WHEREAS, the Successor Company desires to enter into this First Supplemental Indenture forgood and valuable consideration;     NOW, THEREFORE, in consideration of the foregoing and for other good and valuableconsideration, the receipt of which is hereby acknowledged, the Successor Company, the Guarantorsand the Trustee mutually covenant and agree, for the benefit of the Holders of the Notes, asfollows:     1. Defined Terms. As used in this First Supplemental Indenture, terms defined in theIndenture or in the preamble or recital hereto are used herein as therein defined. The words“herein,” “hereof” and “hereby” and other words of similar import used in this First SupplementalIndenture refer to this First Supplemental Indenture as a whole and not to any particular sectionhereof.     2. Assumption of Obligations. In accordance with Article V and Section9.01 of the Indenture, the Successor Company hereby expressly assumes and agrees to pay,perform and discharge when due each and every debt, obligation, covenant and agreement incurred,made or to be paid, performed or discharged by the Predecessor Company under the Indenture and theNotes. The Successor Company hereby agrees to be bound by all the terms, provisions and conditionsof the Indenture and the Notes and agrees that it shall be the successor Company and shall succeedto, and be substituted for, and may exercise every right and power of, the Predecessor Companyunder the Indenture and the Notes.     3. Agreement to Guarantee. Each Guarantor hereby agrees as follows:(a) Along with all other Guarantors named in the Indenture (including pursuant to anysupplemental indentures), to jointly and severally, unconditionally guarantee to eachHolder of a Note authenticated and delivered by the Trustee and to the Trustee and itssuccessors and assigns, that:     (i) the principal of and interest and premium, if any, on the Notes shall bepromptly paid in full when due, whether at maturity, by
 

 
acceleration, redemption or otherwise, and interest on the overdue principalof and interest on the Notes, if any, if lawful, and all other obligations of theIssuer to the Holders or the Trustee thereunder shall be promptly paid in full orperformed, all in accordance with the terms thereof; and     (ii) in case of any extension of time of payment or renewal of any Notes orany of such other obligations, that same shall be promptly paid in full when due orperformed in accordance with the terms of the extension or renewal, whether atstated maturity, by acceleration or otherwise. Failing payment when due of anyamount so guaranteed or any performance so guaranteed for whatever reason, theGuarantors shall be jointly and severally obligated to pay the same immediately.This is a guarantee of payment and not a guarantee of collection.(b) The obligations hereunder shall be unconditional, irrespective of the validity,regularity or enforceability of the Notes or the Indenture or the obligations of the Issuerhereunder or thereunder, the absence of any action to enforce the same, any waiver orconsent by any Holder of the Notes with respect to any provisions hereof or thereof, therecovery of any judgment against the Issuer or any other Guarantor, any action to enforcethe same or any other circumstance which might otherwise constitute a legal or equitabledischarge or defense of a guarantor.(c) Each Guarantor hereby waives: diligence, presentment, demand of payment, filing ofclaims with a court in the event of insolvency or bankruptcy of the Issuer, any right torequire a proceeding first against the Issuer, protest, notice and all demands whatsoever.(d) This Guarantee shall not be discharged except by complete performance of theobligations contained in the Notes, the Indenture and this First Supplemental Indenture.Each Guarantor accepts all obligations applicable to a Guarantor under the Indenture,including Article X of the Indenture (which is deemed incorporated in this FirstSupplemental Indenture and applicable to this Guarantee) and, as applicable, Sections5.01(c) and (d) and Section 5.02 of the Indenture. Each Guarantor acknowledges that byexecuting this First Supplemental Indenture, it will become a Guarantor under the Indentureand subject to all the terms and conditions applicable to Guarantors contained therein.(e) If any Holder or the Trustee is required by any court or otherwise to return to theIssuer, the Guarantors (including the Guarantors party hereto), or any custodian, trustee,liquidator or other similar official acting in relation to either the Issuer or theGuarantors, any amount paid either to the Trustee or such Holder,
 

 
this Guarantee, to the extent theretofore discharged, shall be reinstated in full force andeffect.(f) None of the Guarantors shall be entitled to any right of subrogation in relation to theHolders in respect of any obligations guaranteed hereby until payment in full of allobligations guaranteed hereby.(g) As between each Guarantor, on the one hand, and the Holders and the Trustee, on theother hand, (x) the maturity of the obligations guaranteed hereby may be accelerated asprovided in Article VI of the Indenture for the purposes of this Guarantee, notwithstandingany stay, injunction or other prohibition preventing such acceleration in respect of theobligations guaranteed hereby, and (y) in the event of any declaration of acceleration ofsuch obligations as provided in Article VI of the Indenture, such obligations (whether ornot due and payable) shall forthwith become due and payable by such Guarantor for thepurpose of this Guarantee.(h) Each Guarantor shall have the right to seek contribution from any non-paying Guarantorso long as the exercise of such right does not impair the rights of the Holders under thisGuarantee.(i) Pursuant to Section 10.02 of the Indenture, after giving effect to all other contingentand fixed liabilities that are relevant under any applicable Bankruptcy or fraudulentconveyance laws, and after giving effect to any collections from, rights to receivecontribution from or payments made by or on behalf of any other Guarantor in respect of theobligations of such other Guarantor under Article X of the Indenture, these new Guaranteesshall be limited to the maximum amount permissible such that the obligations of eachGuarantor under its respective Guarantee will not constitute a fraudulent transfer orconveyance.(j) Until released in accordance with Section 10.06 of the Indenture and Section 6 hereof,this Guarantee shall remain in full force and effect and continue to be effective shouldany petition be filed by or against the Issuer for liquidation, reorganization, should theIssuer become insolvent or make an assignment for the benefit of creditors or should areceiver or trustee be appointed for all or any significant part of the Issuer’s assets,and shall, to the fullest extent permitted by law, continue to be effective or bereinstated, as the case may be, if at any time payment and performance of the Notes are,pursuant to applicable law, rescinded or reduced in amount, or must otherwise be restoredor returned by any obligee on the Notes and Guarantee, whether as a “voidable preference,”“fraudulent transfer” or otherwise, all as though such payment or performance had not beenmade. In the event that any payment or any part thereof, is rescinded, reduced, restoredor returned, the Note shall, to the fullest extent permitted by law, be
 

 
reinstated and deemed reduced only by such amount paid and not so rescinded, reduced,restored or returned.(k) In case any provision of this Guarantee shall be invalid, illegal or unenforceable, thevalidity, legality, and enforceability of the remaining provisions shall not in any way beaffected or impaired thereby.(l) Each respective Guarantee shall be a general unsecured senior obligation of theGuarantor, ranking *pari passu*in right of payment with all existing and future SeniorIndebtedness of such Guarantor, if any.(m) Each payment to be made by the Guarantors in respect of their respective Guaranteesshall be made without set-off, counterclaim, reduction or diminution of any kind or nature.     4. Execution and Delivery. Each Guarantor agrees that the Guarantee shall remain infull force and effect notwithstanding the absence of the endorsement of any notation of suchGuarantee on the Notes.     5. Merger, Consolidation or Sale of All or Substantially All Assets of a Guarantor.     (a) Except as otherwise provided in Section 5.01(c) of the Indenture, no Guarantor mayconsolidate or merge with or into or wind up into (whether or not such Guarantor is the survivingcorporation), or sell, assign, transfer, lease, convey or otherwise dispose of all or substantiallyall of its properties or assets, in one or more related transactions, to any Person.     (b) In the case of clause (i) of Section 5.01(c) of the Indenture, the Successor Person willsucceed to, and be substituted for, a Guarantor under the Indenture and such Guarantor’s Guarantee.Notwithstanding the foregoing, any Guarantor may merge into or transfer all or part of itsproperties and assets to another Guarantor or the Issuer.     (c) Upon any consolidation or merger, or any sale, assignment, transfer, lease, conveyance orother disposition of all or substantially all of the assets of the Issuer or a Guarantor inaccordance with Section 5.01 of the Indenture, the successor corporation formed by suchconsolidation or into or with which the Issuer or such Guarantor, as applicable, is merged or towhich such sale, assignment, transfer, lease, conveyance or other disposition is made shall succeedto, and be substituted for (so that from and after the date of such consolidation, merger, sale,lease, conveyance or other disposition, the provisions of the Indenture referring to the Issuer orsuch Guarantor, as applicable, shall refer instead to the successor corporation and not to theIssuer or such Guarantor, as applicable), and may exercise every right and power of the Issuer orsuch Guarantor, as applicable, under the Indenture with the same effect as if such successor Personhad been
 

 
named as the Issuer or a Guarantor, as applicable, herein; *provided*that the predecessorIssuer shall not be relieved from the obligation to pay the principal of and interest on the Notesexcept in the case of a sale, assignment, transfer, conveyance or other disposition of all of theIssuer’s assets that meets the requirements of Section 5.01 of the Indenture.     6. Releases. The Guarantee of each Guarantor shall be automatically andunconditionally released and discharged, and no further action by such Guarantor, the Issuer or theTrustee is required for the release of the Guarantor’s Guarantee, upon satisfaction of all of theconditions set forth in Section 10.06 of the Indenture.     7. No Recourse Against Others. No past, present or future director, officer,employee, incorporator or stockholder of the Issuer or any Guarantor shall have any liability forany obligations of the Issuer or the Guarantors (including the Guarantors party hereto) under theNotes, any Guarantees, the Indenture or this First Supplemental Indenture or for any claim basedon, in respect of, or by reason of, such obligations or their creation. Each Holder by acceptingNotes waives and releases all such liability. The waiver and release are part of the considerationfor issuance of the Notes.     8. Governing Law. THIS FIRST SUPPLEMENTAL INDENTURE SHALL BE GOVERNED BY ANDCONSTRUED IN ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK. THE TRUSTEE, THE SUCCESSORCOMPANY, ANY OTHER OBLIGOR IN RESPECT OF THE NOTES AND (BY THEIR ACCEPTANCE OF THE NOTES) THEHOLDERS AGREE TO SUBMIT TO THE JURISDICTION OF ANY UNITED STATES FEDERAL OR STATE COURT LOCATED INTHE BOROUGH OF MANHATTAN, IN THE CITY OF NEW YORK IN ANY ACTION OR PROCEEDING ARISING OUT OF ORRELATING TO THIS FIRST SUPPLEMENTAL INDENTURE.     9. Counterparts. The parties hereto may sign any number of copies of this FirstSupplemental Indenture. Each signed copy shall be an original, but all of them together representthe same agreement. Delivery of an executed signature page to this First Supplemental Indenture byfacsimile or other electronic transmission shall be effective as delivery of a manually signedcounterpart of this First Supplemental Indenture.     10. Effect of Headings. The Section headings herein have been inserted forconvenience of reference only, are not considered a part of this First Supplemental Indenture andshall in no way modify or restrict any of the terms or provisions hereof.     11. The Trustee. The Trustee shall not be responsible in any manner whatsoever for orin respect of the validity or sufficiency of this First Supplemental Indenture or for or in respectof the recitals contained herein, all of which recitals are made solely by each Guarantor or theSuccessor Company, as the case may be.
 

 
     12. Subrogation. Each Guarantor shall be subrogated to all rights of Holders againstthe Issuer in respect of any amounts paid by such Guarantor pursuant to the provisions of Section 3hereof and Section 10.01 of the Indenture; provided that, if an Event of Default has occurred andis continuing, such Guarantor shall not be entitled to enforce or receive any payments arising outof, or based upon, such right of subrogation until all amounts then due and payable by the Issuerunder the Indenture or the Notes shall have been paid in full.     13. Benefits Acknowledged. Each Guarantor’s Guarantee is subject to the terms andconditions set forth in the Indenture. Each Guarantor acknowledges that it will receive direct andindirect benefits from the financing arrangements contemplated by the Indenture and this FirstSupplemental Indenture and that the guarantee and waivers made by it pursuant to this Guarantee areknowingly made in contemplation of such benefits.     14. Successors. All agreements of the Guarantors in this First Supplemental Indentureshall bind their respective successors, except as otherwise provided in Sections 5.01(c)(i),5.01(d), 5.02 and 10.06 of the Indenture or elsewhere in this First Supplemental Indenture. Allagreements of the Trustee in this First Supplemental Indenture shall bind its successors.     15. Parties. Nothing in this First Supplemental Indenture is intended or shall beconstrued to give any Person, other than the Holders and the Trustee, any legal or equitable right,remedy or claim under or in respect of each Guarantor’s Guarantee or any provision contained hereinor in Article X of the Indenture.     16. Ratification of Indenture; First Supplemental Indentures Part of Indenture.Except as expressly amended hereby, the Indenture is in all respects ratified and confirmed and allthe terms, conditions and provisions thereof shall remain in full force and effect. This FirstSupplemental Indenture shall form a part of the Indenture for all purposes, and every Holder ofNotes heretofore or hereafter authenticated and delivered shall be bound hereby. The Trustee makesno representation or warranty as to the validity or sufficiency of this First SupplementalIndenture or as to the accuracy of the recitals to this First Supplemental Indenture.
 

 
     IN WITNESS WHEREOF, the parties hereto have caused this First Supplemental Indenture to beduly executed, all as of the date first above written.      SRA INTERNATIONAL, INC., as